Explosive-engine.



0. M. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED 050.2 1.1912.

19161911fi$ Patented Nov. 23, 1915,

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O. BERGSTROM.

EXPLOSIVE ENGINE.

APPLICATION FILED DEC. 24. 1912.

Patented Nov. 23, 1915.

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- 0. M. BERGSTROIVI.

EXPLOSIVE ENGINE.

APPLICATION FILED DEL-24,1912

LIWI I@%H Patented Nov. 23, 1915.

3 SHEETS SHEET 3- I FFIN OSCAR BERGSTROM, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO UNIVERSAL MANUFACTURING COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF MINNESOTA.

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Specification of Letters Patent. 7

Patented Nov. 23, 1915.

Application filed December 24, 1912. Serial No. 738,480.

T 0 all whom it may concern:

Be it known that I, OSCAR M. BERGSTROM,

a citizenof the United States, residing at Minneapolis, in the county of Hennepin and v State of Minnesota, have invented certain new and useful Improvements in Explosive- Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertainsto make and use the same.

My invention relates to internal combustion or so-called explosive engines, and has for its object to improve the construction and operation thereof. 7

The engine of the present application involves valve actuating, mechanism of the general type disclosed and broadly claimed in my prior application Serial Number 691,857, filed April 19, 1912.. Specifically, however, the valve actuating mechanism of this application differs from, and is an improvement on the valve actuating mechanism of the said prior application. The arrangement of the inlet and exhaust valves and cooperating portsv is an improvement on the valve mechanism of said rior application,

both in point of higher e ciency in opera tion and in facility of manufacture.

In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.'

Referring to the drawing, Figure 1 is a vertical section taken on the irregular line w ae-yy of Fig. 3; Fig. 2 is a vertical section taken on the irregular line wmzz of Fig. 3; and Fig. 3 is a view partly in plan, and partly in horizontal section, and with some parts removed, and some parts broken away, showing a multi-cylinder engine embodying the invention.

The engine illustrated in the drawings is of the four-cycle multi-cylinder type, and Fig. 3 shows two units or cylinders. The cylinders 1 are, as shown, secured at their lower open ends to crank shaft casings 2. In the engine illustrated, the crank sha-ft casing 2 is formed integral with a hollow base 3 and an offset auxiliary casing 4, and has communication with the former through one or more perforations 5 and with the latter through a tube 6. Each cylinder 1 is formed with vertically extended cylindrical valve seats 7 extended parallel to the axis of the cylinder and located as close thereto, and

to each other, as practicable. The lower extremities of the valve seats 7 are connected by a depending housing 7 u to an opening in the top of the corresponding auxiliary casing 4.. Preferably, the cylinder 1 is pro vlded with a water jacket 8, extending around the upper portion thereof and around the valve seats 7.

The piston 9 which works in the cylinder 8 may be of the usual or any suitable construction. Cylindrical valves 10, preferably formed hollow with open upper ends and closed lower ends, work in the valve seats 7. The said valve seats are connected to the upper end of the cylinder 1 by ports 11, that preferably immediately open into a wide passage 11 (see section cylinder in Flg. 3), which, in turn, directly leads to the upper end of the cylinder. This arrangement of the ports and passage permits a complete and free scavenging action and a freer delivery of the explosive mixture into the cylinder. One of these valves controls inlet or admission and is marked Inlet, while the other, which is preferably an exact duplicate thereof, in structure, controls exhaust and is marked with the word Exhaust. The upper end of the valve seat 7, in which the exhaust valve is mounted, is open to the atmosphere or suitably connected to'an exhaust muffler, while the valve seat 7, in which the inlet valve is mounted will, in practice, be connected to a carbureter or other suitable source of gas or vaporized air supply.

The engine crank shaft 12 is journaled in suitable bearings on the casing 2 and its cranks 12 of which there is, of course, one for each cylinder, are connected to the respective pistons 9 by suitable-connecting rods 13. Extending parallel to the engine crank shaft 12 and journaled in suitable bearings on the auxiliary casing 4 and extending through the latter, is a valve actuating crank shaft 14 which has two cranks 14 and 14 for each cylinder. The crank 14 operates the inlet valve and the crank 14", the ex haust valve, and the latter is preferably set a little more than 100 degrees ahead of the former. The said valve actuating crank shaft 1 1 is driven from the engine crank shaft in the direction of rotation of the latter, but at one-half the speed thereof, by any suitable connections, but, as shown, by

' a sprocket chain 15 which runsover a relatively small sprocket 16 on said engine crank shaft and over a relatively large sprocket 17 on saidvalve actuating crank shaft.

Extended through the upper portion of the auxiliary casing 4 is'a fixed shaft or rod 18 which serves as a fulcrum for valve actuating levers 19 for each crank 14; and 14", and the free ends of said levers are connected by links or connecting rods 20, one to the inlet valve and another to the exhaust valve. The levers 19 are provided with cam slots 21, one of which embraces the crank 14* and the other which embraces the crank 14". The inner portions of these crank engaging slots 21 extend nearly radially in respect to the axis of the fulcrum shaft 18, but the outer extremities of'said"slots are abruptly curved. Both of the levers 19 are preferably made alike, or counterparts, one of the other, so that these levers, as Well as the valves 10 and connecting rods 20, may be interchangeably used.

The cha-mber'3 at the base of the crank shaft chamber 2 serves as an oil well and a considerable amount of oil willpreferably be kept in the bottom of the casing 2 and.

within the auxiliary casing 1. The latter is kept nearly filled with oil, which, when there is an over accumulation, fiows into the main casing 2 through the overflow tube 6.

Operation: The following description of the operation will note the action of a single engine unit, that is, one cylinder with its cooperating inlet and exhaust valves and actuating devices. Attention is first called to Fig. l which shows the positions of the parts approximately at the time of explosion, and when the engine crank shaft is about 25 degrees from its inner dead center. Of. course, for different speeds, the timing of the explosion will be varied, and for slow speeds would usually be set closer to the'dead center. In this position, both the inlet and exhaust valves stand approximately in the same position with a very great lap beyond the cooperating ports 11. Fig. 2 shows the positions of the inlet and exhaust valves and other parts at the finishof the power stroke, at which time the en-- gine crank shaft has moved about 145 degrees, in the direction of the arrows, past what is herein treated as its first inner dead center. The exhaust valve (seeFig. 2), it will be noted, is just ready to open while the inlet valve is still closed with very considerable lap. The exhaust continues while the engine crank shaft is moving from a pointapproximately 145 degrees'past its firstinner dead center to a point approximately 10 degrees past its second inner dead center.

Admission begins, 'as stated, on the second inner dead center of the engine crank shaft and continues for 225 degrees of the move mentthereof, at which time, the inlet valve :until the explosion takes place.

good lap during 280 degrees of the first r0- tation of the engine crank shaft, which includes both the compression and power stroke actions. Thus, the engine makes one complete cycle of operation on the fourcycle plan. Referring again to Fig. 2, it will be noted that the crank 14 which operates on the exhaust valve actuating lever 19 is then located relatively close to the pivotal axis of the said lever, so that it will impart a very rapid movement to the said lever, and hence, Will open the exhaust valve with a very greatly accelerated movement over that which can possibly be obtained by a simple crank or eccentric action. At this same time, the crank 14:, which engages the inlet valve actuating lever 19, engages the curved portion of the slot 21 thereof, and, at this time, imparts very little, if any, movement to the said inlet valve, thereby leaving the same closed for the proper interval, with good lap. 'When the inlet valve closes at the end of the inlet or admission period, the exhaust valve will have already reached its uppermost or extreme closed position, and will remain approximately stationary until the inlet valve reaches approximately its uppermost or inmost position. This insures perfect compression and gives 'a long seal or lap at the time the explosion takes place. The quick opening and closing movements of the valves gives a maximum period of open ports for admission and exhaust and this results in very high efficiency. In practice, I have found that it gives a maximum torque at comparatively low speed, which is known to be very desirable for automobile service and for many other purposes. By ex eriment, I have also found that this same e ciency cannot be obtained by valves operated by single cranks or eccentrics.

The levers 19 which are preferably of'the third class are, of course, bifurcated by the crank engaging slots 21, and these slots have straight portions and curved portions. The

said curved portions, obviously, extend at varying angles to the straight portions and in some instances, the so-called'angular portions might also be formed by straight lines, although the curved formation is preferred. The axial centers of the cranks 14 and 14" move on the line of a circle which is contained within a circle struck from the axes of the shaft 18 through the axial center of the pivotal connections between the levers- 19 and links 20. Also, the said cranks 14 and 1 1 move toward and from the axes of the shaft .18, so that at times when they are imparting the required rapid opening movements to the inlet and exhaust valves, they operate on the shorter effective leverage lengths of the said levers, to thereby accomplish the said rapid movement.

What I claim is:

1. In an explosive engine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylin drical valve seats With axes parallel to the axis of said cylinder, said valve seats having ports connecting the same to said cylinder, of admission and exhaust valves working, one in each of said valve seats, engine driven valve actuating cranks, levers having curved differentially acting cam surfaces engaged, respectively, by said'cranks, and connections between said levers and said inlet and exhaust valves.

2. In an explosive engine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats located side by side and extended parallel to the axis of said cylinder, said valve seats having ports connecting the same to said cylinder, of admission and exhaust valves working one in each of said valve seats, engine driven valve actuating cranks, levers having curved differentially acting cam surfaces engaged, respectively, by said cranks, and connections between said levers and said inlet and exhaust valves.

3. In an explosion engine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats located side by side and extended parallel to the axes thereof, said valve seats having ports connected to said cylinder, of counterpart inlet and exhaust valves, respectively, working in said valve seats,' a valve actuating crank shaft driven from the engine crank shaft at onehalf the speed thereof and having crank: set one ahead of the other, counterpart valve actuating levers mounted on alined pivotal axes and having slots formed with differential-acting cam surfaces engaging the cranks of said valve actuating crank shaft, and links independently connecting said levers to said valves.

4. In an explosive engine, the combination with a cylindery'a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats located side by side and extended parallel to the axes thereof,

said valve seats having ports connected to said cylinder, of counterpart inlet and exhaust valves, respectively, Working in said valve seats, a valve actuating crank shaft driven from the engine crank shaft at onehalf the speed thereof, counterpart levers having slots formed with differential-acting cam surfaces engaging the cranks of said valve actuating crank shaft, and links independently connecting said levers to said valves.

. ently connecting said levers to said valves.

5. In an explosive engine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats located sideby side and extended parallel to the axes thereof, said valve seats having ports connected to said cylinder, of counterpart inlet and exhaust valves, respectively, Working in said valve seats, a valve actuating crank shaft driven from the engine crank shaft at onehalf the speed thereof and having cranks set one ahead of the other, counterpart valve actuating levers mounted on alined pivotal axes and having cam slots engaging the cranks of said valve actuating crank shaft and links independently connecting said levers to said valves, the said valve actuating cranks being arranged to rotate on the line of a circle that is contained within a circle struck from the pivotal axes of said levers through the axes of the pivotal connections between said levers and links.

6. In an explosive engine, the combinationawith a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats located side by side and extended parallel to the axes thereof, said valve seats having ports connected to said cylinder, of counterpart inlet and exhaust valves, respectively, working in said valve seats, a valve actuating crank shaft driven from the engine crank shaft at onehalf the speed thereof and having cranks set one ahead ofthe other counterpart valve actuating levers mounted on alined pivotal axes and having cam slots engaging the cranks of said valve actuating crank shaft, and links independently connecting said levers to said valves, the said valve actuating cranks being arranged to rotate on the line of a' circle that is contained within a circle struck from the pivotal axes of said levers through the axes of the pivotal connections between said levers and links, the slots in said levers having inner portions extending toward and from the pivotal axes of said levers and having outer portions extended at an angle to said inner portions.

'7. In an explosive engine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats extended parallel to the axes thereof, said valve seats having ports connected to said cylinder, of counterpart inlet and exhaust valves, respectively, working in said valve seats, a valve actuating crank shaft driven from the engine crank shaft at one-half the speed thereof and having cranks set one ahead of the other, counterpart valve actuating levers mounted on alined pivotal axes and having slots formed with differential-acting cain surfaces engaging the cranks of said valve actuating crank shaft, and links independ- 8. In an explosive engine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats extended parallel to the axes thereof, said valve seats having ential-acting cam surfaces engaging the A cranks of said valve actuating crank shaft,

and links independently connecting said levers to said valves.

9. In an explosiveegine, the combination with a cylinder, a piston, a crank shaft and connecting rod, said cylinder having cylindrical valve seats extended parallel to the axes thereof, said valve seats having ports connected to said cylinder, of counterpart inlet and exhaust valves, respectively,

working in said valve seats, a valve actuating crank shaft driven from the engine crank shaft at one-half the speed thereof and having cranks set one ahead of the other, counterpart valve actuating levers mounted on alined pivotal axes and having cam slots engaging the cranks of said valve actuating crank shaft and links independently connecting said levers to said valves, the said valve actuating cranks being arranged to rotate on the line of a circle that is contained Within a circle struck from the pivotal axes of said levers through the axes of the pivotal connections between said levers and links.

In testimony whereof I aiiix my signature in presence of two Witnesses.

OSCAR M. BERGSTROM.

' Witnesses:

HARRY D. KILGORE, F. D. MERCHANT. 

